Eighteen months after deployment, the NVMe SSDs in a hyper-converged node have reached 80 % of their wear life. Management wants the drives replaced without taking the server offline. The 1U chassis exposes eight 2.5-inch drive trays that connect to a PCIe backplane as well as two on-board 2280 M.2 slots. Which drive form factor should the technician order to guarantee hot-swap capability through the existing front bays?
U.2 (SFF-8639) NVMe drives are built in a 2.5-inch form factor that mates with a blind-mate backplane, allowing them to be inserted or removed while the server is powered on (hot-plug/hot-swap). M.2 modules attach directly to an internal motherboard socket that the NVMe specification explicitly states is not hot-pluggable. Half-height/half-length (HHHL) add-in cards must be installed in PCIe slots behind the server cover, so servicing requires a power-down. E1.S drives can be hot-swapped but need a specialized EDSFF backplane; standard 2.5-inch bays cannot accept them. Therefore, only the U.2 option meets the hot-swap requirement with the existing chassis.